Rolling mill



Nov. 10, 19594 E. A. NELSON 2,911,864

ROLLING MILL Filed June 5, 1956 2 Sheets-Sheet 1 Nov. 10, 1959 E. A.NELSON 2,911,864

ROLLING MILL Filed June 5, 195e 2 sheets-sheet 2 7 a2 [nreryr EmilNelson,

nited States Patent O M ROLLING MILL Emil A. Nelson, Oklawaha, Fla.

Application June 5, 1956, Serial No. 589,510

Claims. (Cl. 80-16) This invention relates to mills capable of coldrolling steel plates and particularly to mills for work plates or piecesin the form of steel discs operative to taper the disc in thicknesstoward the edges of the disc.

Mills in accord with this invention find particular utility in theforming of steel wheel discs for automobiles and other vehicles.

In the forming of steel discs for wheels, it is desirable that the discsbe of maximum thickness throughout a center portion and that thethickness decrease gradually toward the rim or edge of the disc, andvarious mills have been developed in the past for accomplishing suchtapering of wheel discs. This invention relates to an improved mill foraccomplishing the above operation.

In the tapering of steel plate by cold rolling, high roll pressures arerequired, of the order of 100,000 pounds per roll, for example, whileprecision is'also necessary. The conflicting requirements of heavypressures, rolling and moving parts, precise control and rapid operationmake for large size, complexity and high cost of suitable machines.

It is a general object of this invention to provide a mill for coldrolling steel plate of improved simplicity of construction and capableof greater precision of operation, and operative to complete thetapering of the plate more rapidly than prior art machines.

It is desirable in disc tapering Imills that the untapcred disc workpiece be quickly and easily loadable in or on the mill and as readilyremovable therefrom following the tapering operation, and mills whereinthe disc is placed on a tapered table and subjected thereon to rollingby an overhead pressure roll have been heretofore suggested which havethe advantage of relatively rapid loading, although unloading thereoftends to be difficult. It has also been known to bring two similar rollsinto contact with opposite faces of a disc, the disc being held, usuallyin vertical position, by a rotatable center clamp', the two rollssqueezing the discl therebetween. In mills of the latter type, loadingand unloading are slow and the application of suiiicient pressure to therolls is diiiicult, requiring very heavy construction.

In accord with this invention the work piece is supported in horizontalposition on a simple spincHe and is tapered by the action of relativelynarrow rolls engaging the under surface of the work, and movableradially thereof, working against broad overhead idler rolls sopositioned that the work-contacting idler roll surfaces are inclined atsubstantially the desired angle of taper.

The novel features which are believed to be characteristic of thisinvention are set forth with particularity in the appended claims. Theinvention itself, however, both as to its organization and method ofoperation, together with further objects and advantages thereof, maybest be understood by reference to the following description taken inconnection with the accompanying drawings, in which:

Fig."1 is a partially sectional front elevation of a mill in accord withthis invention; f

Patented Nov. 10, 1959 Fig. 2 is a partially sectional end View of themill, taken along line 2-2 of Fig. 1;

lFig. 3 is a fragmentary front elevational view of the mill illustratingthe operation thereof;

Fig. 4 is an exploded view showing details of a portion of theadjustable thickness regulating mechanism of the mill;

Fig. 5 is a perspective view of a finished tapered disc work piece,shown partially broken away; and

Fig. 6 is a schematic diagram of a control mechanism for controlling theoperating cycle of the mill.

As seen in Fig. 1, the mill 1 comprises a base l2 having smoothhorizontal tracks -3 and 4 extending radially outwardly from oppositesides of the base 5 of a vertical fixed spindle y6. The spindlecomprises an upper flanged portion 7 adapted to receive and rotatably tosupport in horizontal position an untapered steel plate work piece 8,

the work piece being preferably centrally apertured and preferably ofilat disc shape.

Two identical driven roll units 9 and 10 are provided to rollhorizontally along respective tracks 3 and 4. Driven roll unit 9, towhich unit 10 is identical, cornprises a carriage 1,1 supported on heavywheels 12 which roll on track 3. A heavy roller bearing block 13, havingbearing rollers I14 therein, and a roller drive motor 15 are rigidlyattached to the upper surface of carriage 11, and motor 15 is coupled,through coupling 16, to drive a roller shaft 17 supported in 'bearingblock 13 by bearing rollers 214. Shaft 17 carries a narrow formingroller `18 in position to engage the under surface 19 of the work pieceI8 adjacent spindle 6 and, as unit 9 is moved outwardly along its track,the roller 18 moves outwardly across the surface of the work in ahorizontal direction axially of the shaft .17 and roller 18. Inward andoutward movement of unit 9 is obtained by means of a hydraulic liquid orcompressed air ram or motor 20 fixed to base 2 'by bolts, such as bolt21, and connected, as by drive rod 22, to the carriage 11. Pressurefluid is supplied through tubes 23 and 24 alternatively to operate ram20 in the desired direction.

Ram 25 and rod 26 are arranged to roll lunit 10 toward and away fromspindle 6, thereby to move `driven roller 27 in the direction of itsaxis across the under surface 19 of the work piece in the mannerdescribed in connection with ram 20, unit 9 and roller 18.

Base 2 desirably comprises a pair of side wall portions 28, '29 servingas track guides and shields for the' rollers of the carriages 11. Fourupstanding guide and overhead frame supporting posts, such as posts 30,31

and 32, are rigidly aflixed to and extend vertically up-` wardly frombase 2. The posts rigidly support an overhead frame or assembly 33 abovethe work-supporting portion 7 of the spindle, being attached to theframe by suitable nuts, such as nut 35, which are threaded on the posts.

The four posts are approximately equally spaced about the axis ofspindle 6,-and about the work piece 8,

and serve as vertical guides for an idler roll carrier member 36. Ashaft 37 extends horizontally through ing rollers, such as roller 40.Idler roll 38 is seenl to be disposed in opening 41 in the carrier inwhich the roll fits suiiiciently closely to prevent appreciable end playof the roll. End play may also'be minimized by utilizing a bearingdesigned in a known manner to have little end play and to take endthrust.

The lower surface portion of roll 38 which contacts the upper surface 42of work piece 8 is upwardly and inwardly inclined toward the axis ofVspindle `6 at substantially 'the desired taper angle of the finisheddisc.'

Thus the lower surface portion of the roll may be at an angle to thehorizontal of from a fraction of 1 to as much as about 3 or 4. In thepreferred embodiment illustrated herein, the upward inclination of thelower idler roll surface is obtained by utilizing frusto-conical idlerrolls rotatable about the horizontal axis of journal shaft 37. It willbe apparent that the roll surface may depart slightly from a trueconical surface if desired to provide a varying final taper of the workpiece. It will also be apparent that the inclination of the lower rollsurface is dependent on the orientation of the axis of the roll, withrespect to the horizontal.

Roll 39 is preferably identical to roll 38 and is identically arrangedon journal shaft 37. Roll 39 contacts work piece 8 directly opposite theportion contacted by roll 38 since the rolls are preferably coaxiallydisposed on an axis intersecting the vertical axis of spindle 6. Theaxis of roll 39 and the axis of roll 38, in the arrangement shown in thedrawings, are in a vertical plane including and defined by the verticalaxis of spindle 6 and the horizontal aligned axes of the driven rolls 18and 27. However, slight departures from such alignment may be desired incertain applications of the mill.

Carrier 36 is mounted to a piston rod 43 by means of rod flange 44 andbolts, such as bolt 45. Rod 43 extends upwardly from the carrier andcarries a piston 46 disposed in a hydraulic fluid or air cylinder 47.Cylinder 47 is preferably formed as a part of frame 33 and has a lowerpacking arrangement 48 for sealing rod 43. Rod 43 comprises a preferablyreduced diameter externally threaded upper portion 49 which extends,through packing or seal arrangement 50, upwardly through the upper wallor top 51 of the cylinder.

It will be apparent that forced downward movement of carrier 36 may beaccomplished by introduction of pressure fiuid through upper tube 52into cylinder 47, while the carrier may be raised by introduction offluid through lower tube 53. The limit of downward movement of carrier36 is established by an adjustable preset split nut 54 threaded on theupper end portion 49 of the piston rod, and by adjustable annular camcollar members 55 and 56. 'Ihe lower collar member 55 rests on the upperend wall 51 of the cylinder and upper collar 56 has a lower circular camface 57 adjustably engaging and in register with upper circular cam face58 of collar 55. Upper collar 56 has a projecting tab 59 so disposed ina vertical slot 60 of an outer annular frame portion 61 as to beattached or keyed to the frame in a manner to prevent rotation of thecollar, while arm 62 extending laterally outwardly from collar 55through horizontal slot 63 permits limited rotation thereof by means ofa hydraulic expansible chamber adjusting mechanism indicated generallyat 64.

Rotation of collar 55 by means of mechanism 64 through interaction ofcam faces 57, 58 raises or lowers the upper face 65 of collar 56 inaccord with direction of rotating of collar 55, and nut 54, whichextends outwardly or laterally from the rod, in meeting face 65,functions as a stop to limit the downward travel of rod 43'and,accordingly, of carrier 36. Coarse adjustment of the limit of downwardtravel of carrier 36 is accomplished by rotaating nut 54 on rod portion49 in a direction to raise or lower the nut thereon as desired.

Handle 66 of nut 54 provides a convenient means for rotating the nut,and, as shown in Fig. 2, the nut 54 is preferably split and providedwith a clamping bolt 67 by which it is locked against inadvertentturning on rod portion 49.

lFig. 2 further discloses details of the mechanism 64 for making fineadjustments of the lower travel limit of carrier 36. The adjustingmechanism is mounted on an extension 68 of the upper frame assembly 33and comprises a double acting hydraulic uid or air ram or motor 69having two pressure fluid'inlets 70 and 71 and a piston rod 72 connectedto arm 62 of cam collar 55. The ram is anchored to frame extension 68 bymeans of a small post 68a. Rod 72 is threaded to carry suitable locknuts 73 as stops cooperating with suitable bosses, such as boss 74, tolimit the permitted travel of rod 72 or, if desired, to lock rod 72 in apredetermined adjusted position.

The several elements and assemblies of the mill are similarly identifiedthroughout the figures of the drawings to assist in comparisons betweenthe several views, and the description of each figure will be understoodto be equally applicable to the similarly identified portions of themill in other figures.

By comparing Figs. l and 2 it will be noticed that idler rolls 38 and 39are disposed for rotation about respective axes which lie in therespective vertical plane passing through the axis of the respectiveunderlying driven roll 18 and 27. Thus roll 39 contacts the work piecedirectly above roll 27. Since shaft 37, in the disclosed embodiment,provides a journal for both of rolls 38 and 39, these idler rolls arecoaxially arranged, as are driven rolls 18 and 27, and it will beapparent that all of the rolls rotate about axes which lie in a singlevertical plane, and that this plane further includes the coincident axisof rotation of the work piece and axis of spindle 6.

Tracks 3 and 4 are horizontal and bounded by upstanding edge portions28, 29 and the units 9 and 10 are movable in the horizontal directionsof the common driven roll axis.

Fig. 3 shows the mill in operation to taper work piece 8. Carrier 36 isin lowered position, with nut 54 engaged with cam roller 56 and withidler rolls 38 and 39 in contact with the upper face 42 of the work.Pressure of rolls 38 and 39 on the Work may be determined in accord withthe differential pressure between tubes 52 and 53 and thus, if thedegree of taper and hardness of the work piece material are such as tomake impractical the complete tapering function in one outward pass ofrollers 18 and 27, the rollers 38 and 39 may be forced upwardly from thelower limit position as rollers 38 and 39 progress outwardly.

It is preferred, when more than one pass is necessary, to remove some orall of the downward pressure of rolls 38, 39 on the work piece, byappropriately adjusting the cylinder pressures through tubes 52 and 53during the inward travel of the driven rolls and again to increase thepressure during the working travel of the drive rolls in the directionof arrows 75 and 76 respectively.

It is also possible to adjust cam collar 55 in progressive steps toprogressively lower the limit position of the idler rolls for eachworking pass of the driven rollers until on -a final pass the work piecehas the appropriate desired taper.

The operating surfaces of driven rolls 18 and 27 are sufficiently narrowto contact only a limited radial portion of the work and, for example,may be one-half or less of the width of the idler rolls. The drivenrolls are slightly bevelle'd or rounded along the outer edges as at '77to reduce marking or grooving of the undcrsurface of the work.

Cam collars 55 and 56 are shown in detail in Fig. 4, and it will be seenthat cam surface 57 of collar 56 is .arranged to fit against cam surface58 of collar 55, with each inclined surface portion, such as portion 78,of surface 57 adapted to lie against `a corresponding inclined surfaceportion, such portion 79, of surface 58.

A finished tapered disc work piece 8 is shown in Fig. 5, having an uppersurface portion 42 inclined to the horizontal flat under surface 19 atsubstantially the same angle as the angle of inclination of the lowerworking surface of the idler rolls of the mill. The finished work piecewill have an overall diameter somewhat greater than the originaldiameter of the original untapered work piece. Central aperture of thefinished work piece would be originally formed in the blank to permitsupport of the work piece on the mill spindle.

A suitable control arrangement for the mill is shown in Fig. 6 andoperation of the mill through a typical cycle is controlled by thisarrangement in response to momentary closure of starting switch 81 toapply energizing current to coil 82 of control relay 83 from electricpower bus 84. Timing motor 85 is started in response to actuation ofrelay 83 and the motor initiates rotation of switch cams 86, 87, 88 and89. Cam 86 closes its switch 90 establishing a holding circuit in shuntwith starting switch 81 to maintain relay 83 in energized conditionthrough the cycle. Substantially simultaneously switch 91 is closed bycam 89 causing energization of the coil 92 of an idler roll pressurecontrol valve 93. Valve 93 operates in response to energization of coil92 to admit pressure fluid from a pump 94 into tube 52, thereby to forcecarrier 36 downwardly, and simultaneously to relieve pressure in tube 53through exhaust or return line 95. A pressure relief valve 96 may beconnected to pump 94 to limit the maximum applicable to the controllingrams and cylinders of the mill and its control system.

Shortly after carrier 36 is lowered as a result of the actuation ofvalve 93, cam 88 closes its switch 97 energizing solenoid valves 98 and99 to admit pressure iluid from pump 94 into line 23 of ram 20 and line100 of ram 2S to provide outward movement of the driven roll carriages.Adjustable regulating valves 101 and 102 are arranged in the branchlines 103 and 104 connecting pump 94 with the respective carriagecontrol Valves 98 and 99 to permit speed control and balancing ofoper-ation of the carriage transporting rams.

The first outward traverse of the driven rolls may be accomplished withthe cam collars in a first position co1'- responding to the positionshown in Fig. 2, for example. The upper collar surface, in thisposition, stops the nut 54 with the idler rolls at what may be termed -afirst pass Working level, while movement of arm 62 to the right as seenin Fig. 2 will lower the limit position of the idler rolls, whereby theymay assume a second pass working level which is, for example, la smallfraction of an inch lower than the rst pass Working level.

Referring again to Fig. 6, it will be seen that cams 88 and 89 openswitches 97 and 91 after a predetermined period of operation, whichshould be timed to permit the driven roll carriages to have reached thedesired outer limit position. Each of valves 98 and 99 may be identicalto valve 93 and provided with a return spring such as spring 105 ofvalve 93, and, as energizing current for the valves 93, 98 and- 99 isinterrupted by the opening of switches 91 and 97, the valves return torest position, permitting pressure iluid to enter line 53, to raise theidler roll carrier, and lines 24 and 106 of rams 20 and 25,respectively, thereby to cause transporting of the driven roll carriersto their inward limit positions. Simultaneously, fluid may exhaust, ifair, or return, if a liquid, through lines 52 and 107 of the carrierpressure cylinder and valve 93, through lines 23 and 108 of the ram 20and valve 98, and through lines 100 and 109 of ram 25 and valve 99.

As carrier 36 starts to rise in response to opening of switch 91, cam 87closes its switch 118 to energize the solenoid 111 of a spring returnvalve 112, thereby acting to supply pressure fluid through pressure pumpline 113 and adjustably preset reduction valve 114 to line 70 of ram 69,and, simultaneously, to relieve pressure in line 71 to exhaust or returnline 115. Motion of rod 72 which results from actuation of valve 112steps the lower cam collar into position to establish the second passworking level limit for the idler rolls.

Following completion of the movement of rod 72, cam 89 again closesswitch 91 to energize coil 92 and actuate the valve against the bias ofspring 105, reestablishing the pressure fluid connection to line 52 andthe pressure relief connection from line 53 to line 95. Thereafter, thecarrier 36 having reached its second pass limit posi'- tion, cam 88again closes switch 97 to actuate valves 98 and 99, permitting escape ofuid from line 106 to return or exhaust line 116 and from line 24 toreturn or exhaust line 117, and application of pressure fluid to lines23 and 100.

Toward the end of the cycle, after the second working traverse of thedriven roll carriages, switches 91, 97 and 110 are all opened by theirrespective associated cams, thereby causing spring return of each ofvalves 93, 98, 99 and 112 into positions to raise idler roll carrier 36,to move the driven roll carriages inwardly toward the Work supportingspindle and to rotate the lower cam collar into position to reestablishthe first pass limit position for the idler roll carrier. Cam 86 finallyreturns with the other switch cams to the positions shown in Fig. 6,switch 90 opens and relay 83 drops out. The tapered work piece may nowbe replaced by a new work piece on which the mill is to operate throughthe next cycle.

It is assumed in the above described sequences of an exemplary operatingcycle that pump 94 shown in Fig. 6 is constantly operating, and that themotors for driving rolls 18 and 27, such :as motor 15, are alsoconstantly operating.

Various modifications of the control arrangement will occur to personsskilled in the art to accord with the number of passes of the drivenrolls across each disc, the extent of taper desired and other factors.

It will be seen that the mill of this invention comprises driven rollsmovable on their carriages directly backwardly and forwardly, oroutwardly and inwardly, from and toward the spindle, and furthercomprises a pair of idler rolls each rotatable on an axis fixed withrespect to a carrier and the carrier need be moved only verticallyupwardly and downwardly. The mill, accordingly, requires only simplemotions of the main movable parts, the parts are of relatively simpledesign and may be easily constructed with sufficient sturdiness towithstand the high forming pressures required for rapid forming of thework piece. It will also be apparent that the machine is readilyadjustable, for example, to compensate for wear of the rolls, i.e. byadjusting nut 54 or by adjusting the positions of nuts 73 on rod 72, andparts subject to wear are k readily replaceable when necessary with aminimum of mill disassembly.

While only certain preferred embodiments of this invention have beenshown and described by way of illustration, many modifications willoccur to those skilled in the art and it is, therefore, desired that itbe understood that it is intended in the appended claims to cover allsuch modifications as fall within the true spirit and scope of thisinvention.

What is claimed as new and what it is desired to secure by LettersPatent of the United States is:

1. A mill for cold rolling steel plates comprising a base, a spindlefixed in position relative to said base, a plurality of vertical membersfixed to and extending upward from said base and spaced about saidspindle, an overhead frame assembly supportedly affixed to said verticalmembers and disposed above said spindle, said base having a pair oftracks extending horizontally outwardly on opposite sides of saidspindle, a pair of units, rollers supporting one of said units on onesaid track and thek other said unit on the other said track, each saidunit comprising electric motor power means, a roll driven by said powermeans, and means supporting said roll at a xed distance above saidrollers, force means for moving said units along said tracks toward andaway from said spindle, said spindle comprising means to -support a workplate generally in a horizontal plane with its lower surface engagingthe upper surface of said rolls, a pair of idler rolls disposed abovesaid horizontal plane and adapted and arranged to bear against the uppersurface of said work plate, an idler roll carrier member, axle meansengaged in said carrier member supporting said idler rolls on saidcarrier member for free axial rotation, each said idler roll having alower work-contacting surface, said axle means being oriented to disposethe rotational axis of each said idler roll substantially verticallyabove the axis of rotation of a respective one of said driven rolls andto dispose the lower work-contacting surface of each said idler roll inan inwardly and less than 4 upwardly inclined position, said `framecomprising a vertical operating cylinder, said cylinder having a pistonconnected to said carrier member and operative to force said carriermember vertically downwardly, said carrier being in guided engagementwith said vertical members.

2. in a rolling mill having rolls of lixed height for rolling againstone face of the work, the combination of a movable carrier having rollsrotatably carried thereon for rolling against the opposite face of thework, a piston rod connected to said carrier, a piston on said rod,means to apply hydraulic pressure to said piston in a direction to forcesaid carrier toward the work, a stop element affixed to said rod andextending laterally outwardly therefrom, a fixed frame having a portionspaced in said direction from said stop element and disposed adjacentsaid rod, a pair of annular cam collars surrounding said rod disposedbetween said frame portion and said stop element, each said collarhaving a respective circular cam face and said faces being inregistering contact with each other, and means connected with saidcollars for adjusting the rotational position of one with respect to theother said collar.

3. The combination of claim 2 wherein the means connected with thecollars for adjusting the rotational position of one with respect to theother said collar comprises an expansible chamber device having aportion connected to the frame means and a second relatively movableportion connected to said one collar and further comprises meansinterconnecting said frame means and said other collar, selectivelyoperable means for supplying pressure fluid to said expansible chamberdevice, and stop means engageable by said second portion of saidexpansible chamber device.

4. A metal disc tapering mill comprising a base, an upstanding spindlecarried by said base, at least two vertical members fixed to andextending upwardly from said base and disposed outwardly of and onopposite sides of said spindle, an overhead frame assembly supportedlyaffixed to said vertical members spacedly above said base and includingan upright cylinder, said base including a first xed track extendinggenerally horizontally outwardly from said spindle in one directiontherefrom and a second fixed track extending generally horizontallyoutwardly from said spindle in the opposite direction, a rst carriageunit having supporting rollers engaged on said first track and a secondcarriage unit having supporting rollers engaged on said second track,each said carriage unit comprising a respective work-engageable narrowfaced roll, respective means rotatably mounting said roll thereon at afixed distance above the suppoiting rollers and respective motor meanscarried thereon for driving the respective roll thereof, force means formoving each said carriage unit along its respective track toward andaway from said spindle, said spindle comprising means for supporting awork piece disc above said rolls to be contacted on its lower face bysaid rolls, a carrier member, means disposed above said spindle mountingsaid carrier member on said overhead frame assembly, said mounting meanscomprising a piston disposed in said cylinder and means fixing saidcarrier member to said piston and disposing said carrier below saidcylinder and above said spindle-supported work piece disc, two idlerrollers rotatably mounted on and having work surfaces wider than thework faces of said rolls protruding below said carrier member andadapted and arranged t0 engage the upper face of the work piece disc,each said roller being generally aligned above a respective one of saidrolls, amd means for introducing pressure fluid into said cylinder abovesaid piston to force said carrier member downwardly thereby forcedly toengage said carrier member rollers against the upper face of the workpiece disc.

5. In a steel plate disc tapering mill, a pair of narrow driven rolls ofequal diameters, driving means supporting said rolls for driven rotationabout respective predetermined horizontal, generally aligned axes, saidmeans comprising means for moving each said roll axially inwardly andoutwardly toward and away from the other between respectivepredetermined limits of travel, a pair of idler rolls, each said idlerroll having an elongated surface between said limits of travel, of arespective corresponding one of said driven rolls, each said idler rollbeing freely rotatable on an axis vertically displaced above the axis ofthe respective driven roll, each said idler roll having a lower surfaceportion facing the respective driven roll and the axis of each idlerroll being oriented to dispose said lower surface portion thereof at anangle of less than about 4 degrees to the horizontal and extendingdownwardly at such angle in a respective outward direction, a carriermember, said idler rolls being rotatably mounted on said carrier memberfor rotation about their respective said axes, a hydraulic cylinderhaving a substantially vertical axis, a piston vertically movable insaid cylinder, a piston rod connecting said carrier to said piston, saidcylinder having a top above said piston, said rod extending upwardly ofsaid piston and through and above the top of said cylinder and having anexternally threaded portion above said cylinder, a nut threaded on saidthreaded portion, two collars interposed between said nut and the top ofsaid cylinder, each said collar having a respective circular cam surfaceand said cam surfaces being in registering engagement, and adjustablemeans connected to said collars operable to adjust the rotationalposition of one said cam surface with respect to the other.

References Cited in the le of this patent UNITED STATES PATENTS1,350,057 Bell Aug. 17, 1920 1,588,146 Schlumpf June 8, 1926 1,698,373Nelson Jan. 8, 1929 1,788,551 Smith Jan. 13, 1931 2,091,578 Batie Aug.31, 1937 2,379,840 Stuhlman July 3, 1945 2,406,219 Hight et al. Aug. 20,1946 2,647,423 Horn Aug. 4, 1953

